The present invention relates to a semiconductor memory device operated synchronously with clock signals, and more particularly to an output circuit used therein to expand the duration period of the output signal.
In a conventional semiconductor memory device controlled by clock signals such as a metal-oxide semiconductor (MOS) dynamic memory device, since the output signal is output and shut off synchronously with the turning on and off of a clock signal, such as a column address strobe signal, respectively, the duration period of the output signal is short when the frequency of the clock signals is high. Therefore, it is impossible to make the frequency of the clock signals too high, limiting the operation speed of the memory device.